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b4a11b2033
Reproduce environment: network with 3 VM linuxs is connected as below: VM1<---->VM2(latest kernel 6.5.0-rc7)<---->VM3 VM1: eth0 ip: 192.168.122.207 MTU 1500 VM2: eth0 ip: 192.168.122.208, eth1 ip: 192.168.123.224 MTU 1500 VM3: eth0 ip: 192.168.123.240 MTU 1500 Reproduce: VM1 send 1400 bytes UDP data to VM3 using tools scapy with flags=0. scapy command: send(IP(dst="192.168.123.240",flags=0)/UDP()/str('0'*1400),count=1, inter=1.000000) Result: Before IP data is sent. ---------------------------------------------------------------------- root@qemux86-64:~# cat /proc/net/snmp Ip: Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates Ip: 1 64 11 0 3 4 0 0 4 7 0 0 0 0 0 0 0 0 0 ...... ---------------------------------------------------------------------- After IP data is sent. ---------------------------------------------------------------------- root@qemux86-64:~# cat /proc/net/snmp Ip: Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates Ip: 1 64 12 0 3 5 0 0 4 8 0 0 0 0 0 0 0 0 0 ...... ---------------------------------------------------------------------- "ForwDatagrams" increase from 4 to 5 and "OutRequests" also increase from 7 to 8. Issue description and patch: IPSTATS_MIB_OUTPKTS("OutRequests") is counted with IPSTATS_MIB_OUTOCTETS ("OutOctets") in ip_finish_output2(). According to RFC 4293, it is "OutOctets" counted with "OutTransmits" but not "OutRequests". "OutRequests" does not include any datagrams counted in "ForwDatagrams". ipSystemStatsOutOctets OBJECT-TYPE DESCRIPTION "The total number of octets in IP datagrams delivered to the lower layers for transmission. Octets from datagrams counted in ipIfStatsOutTransmits MUST be counted here. ipSystemStatsOutRequests OBJECT-TYPE DESCRIPTION "The total number of IP datagrams that local IP user- protocols (including ICMP) supplied to IP in requests for transmission. Note that this counter does not include any datagrams counted in ipSystemStatsOutForwDatagrams. So do patch to define IPSTATS_MIB_OUTPKTS to "OutTransmits" and add IPSTATS_MIB_OUTREQUESTS for "OutRequests". Add IPSTATS_MIB_OUTREQUESTS counter in __ip_local_out() for ipv4 and add IPSTATS_MIB_OUT counter in ip6_finish_output2() for ipv6. Test result with patch: Before IP data is sent. ---------------------------------------------------------------------- root@qemux86-64:~# cat /proc/net/snmp Ip: Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates OutTransmits Ip: 1 64 9 0 5 1 0 0 3 3 0 0 0 0 0 0 0 0 0 4 ...... root@qemux86-64:~# cat /proc/net/netstat ...... IpExt: InNoRoutes InTruncatedPkts InMcastPkts OutMcastPkts InBcastPkts OutBcastPkts InOctets OutOctets InMcastOctets OutMcastOctets InBcastOctets OutBcastOctets InCsumErrors InNoECTPkts InECT1Pkts InECT0Pkts InCEPkts ReasmOverlaps IpExt: 0 0 0 0 0 0 2976 1896 0 0 0 0 0 9 0 0 0 0 ---------------------------------------------------------------------- After IP data is sent. ---------------------------------------------------------------------- root@qemux86-64:~# cat /proc/net/snmp Ip: Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates OutTransmits Ip: 1 64 10 0 5 2 0 0 3 3 0 0 0 0 0 0 0 0 0 5 ...... root@qemux86-64:~# cat /proc/net/netstat ...... IpExt: InNoRoutes InTruncatedPkts InMcastPkts OutMcastPkts InBcastPkts OutBcastPkts InOctets OutOctets InMcastOctets OutMcastOctets InBcastOctets OutBcastOctets InCsumErrors InNoECTPkts InECT1Pkts InECT0Pkts InCEPkts ReasmOverlaps IpExt: 0 0 0 0 0 0 4404 3324 0 0 0 0 0 10 0 0 0 0 ---------------------------------------------------------------------- "ForwDatagrams" increase from 1 to 2 and "OutRequests" is keeping 3. "OutTransmits" increase from 4 to 5 and "OutOctets" increase 1428. Signed-off-by: Heng Guo <heng.guo@windriver.com> Reviewed-by: Kun Song <Kun.Song@windriver.com> Reviewed-by: Filip Pudak <filip.pudak@windriver.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2060 lines
52 KiB
C
2060 lines
52 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Neighbour Discovery for IPv6
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* Linux INET6 implementation
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*
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* Authors:
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* Pedro Roque <roque@di.fc.ul.pt>
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* Mike Shaver <shaver@ingenia.com>
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*/
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/*
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* Changes:
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*
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* Alexey I. Froloff : RFC6106 (DNSSL) support
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* Pierre Ynard : export userland ND options
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* through netlink (RDNSS support)
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* Lars Fenneberg : fixed MTU setting on receipt
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* of an RA.
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* Janos Farkas : kmalloc failure checks
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* Alexey Kuznetsov : state machine reworked
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* and moved to net/core.
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* Pekka Savola : RFC2461 validation
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* YOSHIFUJI Hideaki @USAGI : Verify ND options properly
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*/
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#define pr_fmt(fmt) "ICMPv6: " fmt
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/sockios.h>
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#include <linux/sched.h>
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#include <linux/net.h>
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#include <linux/in6.h>
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#include <linux/route.h>
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#include <linux/init.h>
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#include <linux/rcupdate.h>
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#include <linux/slab.h>
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#ifdef CONFIG_SYSCTL
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#include <linux/sysctl.h>
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#endif
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#include <linux/if_addr.h>
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#include <linux/if_ether.h>
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#include <linux/if_arp.h>
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#include <linux/ipv6.h>
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#include <linux/icmpv6.h>
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#include <linux/jhash.h>
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#include <net/sock.h>
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#include <net/snmp.h>
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#include <net/ipv6.h>
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#include <net/protocol.h>
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#include <net/ndisc.h>
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#include <net/ip6_route.h>
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#include <net/addrconf.h>
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#include <net/icmp.h>
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#include <net/netlink.h>
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#include <linux/rtnetlink.h>
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#include <net/flow.h>
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#include <net/ip6_checksum.h>
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#include <net/inet_common.h>
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#include <linux/proc_fs.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv6.h>
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static u32 ndisc_hash(const void *pkey,
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const struct net_device *dev,
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__u32 *hash_rnd);
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static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
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static bool ndisc_allow_add(const struct net_device *dev,
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struct netlink_ext_ack *extack);
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static int ndisc_constructor(struct neighbour *neigh);
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static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
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static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
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static int pndisc_constructor(struct pneigh_entry *n);
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static void pndisc_destructor(struct pneigh_entry *n);
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static void pndisc_redo(struct sk_buff *skb);
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static int ndisc_is_multicast(const void *pkey);
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static const struct neigh_ops ndisc_generic_ops = {
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.family = AF_INET6,
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.solicit = ndisc_solicit,
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.error_report = ndisc_error_report,
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.output = neigh_resolve_output,
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.connected_output = neigh_connected_output,
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};
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static const struct neigh_ops ndisc_hh_ops = {
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.family = AF_INET6,
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.solicit = ndisc_solicit,
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.error_report = ndisc_error_report,
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.output = neigh_resolve_output,
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.connected_output = neigh_resolve_output,
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};
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static const struct neigh_ops ndisc_direct_ops = {
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.family = AF_INET6,
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.output = neigh_direct_output,
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.connected_output = neigh_direct_output,
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};
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struct neigh_table nd_tbl = {
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.family = AF_INET6,
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.key_len = sizeof(struct in6_addr),
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.protocol = cpu_to_be16(ETH_P_IPV6),
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.hash = ndisc_hash,
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.key_eq = ndisc_key_eq,
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.constructor = ndisc_constructor,
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.pconstructor = pndisc_constructor,
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.pdestructor = pndisc_destructor,
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.proxy_redo = pndisc_redo,
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.is_multicast = ndisc_is_multicast,
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.allow_add = ndisc_allow_add,
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.id = "ndisc_cache",
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.parms = {
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.tbl = &nd_tbl,
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.reachable_time = ND_REACHABLE_TIME,
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.data = {
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[NEIGH_VAR_MCAST_PROBES] = 3,
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[NEIGH_VAR_UCAST_PROBES] = 3,
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[NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
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[NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
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[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
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[NEIGH_VAR_INTERVAL_PROBE_TIME_MS] = 5 * HZ,
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[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
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[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
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[NEIGH_VAR_PROXY_QLEN] = 64,
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[NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
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[NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
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},
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},
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.gc_interval = 30 * HZ,
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.gc_thresh1 = 128,
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.gc_thresh2 = 512,
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.gc_thresh3 = 1024,
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};
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EXPORT_SYMBOL_GPL(nd_tbl);
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void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data,
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int data_len, int pad)
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{
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int space = __ndisc_opt_addr_space(data_len, pad);
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u8 *opt = skb_put(skb, space);
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opt[0] = type;
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opt[1] = space>>3;
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memset(opt + 2, 0, pad);
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opt += pad;
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space -= pad;
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memcpy(opt+2, data, data_len);
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data_len += 2;
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opt += data_len;
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space -= data_len;
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if (space > 0)
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memset(opt, 0, space);
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}
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EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
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static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
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const void *data, u8 icmp6_type)
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{
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__ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
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ndisc_addr_option_pad(skb->dev->type));
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ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
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}
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static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
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void *ha,
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const u8 *ops_data)
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{
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ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
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ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
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}
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static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
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struct nd_opt_hdr *end)
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{
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int type;
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if (!cur || !end || cur >= end)
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return NULL;
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type = cur->nd_opt_type;
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do {
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cur = ((void *)cur) + (cur->nd_opt_len << 3);
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} while (cur < end && cur->nd_opt_type != type);
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return cur <= end && cur->nd_opt_type == type ? cur : NULL;
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}
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static inline int ndisc_is_useropt(const struct net_device *dev,
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struct nd_opt_hdr *opt)
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{
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return opt->nd_opt_type == ND_OPT_PREFIX_INFO ||
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opt->nd_opt_type == ND_OPT_RDNSS ||
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opt->nd_opt_type == ND_OPT_DNSSL ||
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opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
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opt->nd_opt_type == ND_OPT_PREF64 ||
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ndisc_ops_is_useropt(dev, opt->nd_opt_type);
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}
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static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
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struct nd_opt_hdr *cur,
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struct nd_opt_hdr *end)
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{
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if (!cur || !end || cur >= end)
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return NULL;
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do {
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cur = ((void *)cur) + (cur->nd_opt_len << 3);
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} while (cur < end && !ndisc_is_useropt(dev, cur));
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return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
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}
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struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
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u8 *opt, int opt_len,
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struct ndisc_options *ndopts)
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{
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struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
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if (!nd_opt || opt_len < 0 || !ndopts)
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return NULL;
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memset(ndopts, 0, sizeof(*ndopts));
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while (opt_len) {
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int l;
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if (opt_len < sizeof(struct nd_opt_hdr))
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return NULL;
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l = nd_opt->nd_opt_len << 3;
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if (opt_len < l || l == 0)
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return NULL;
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if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
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goto next_opt;
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switch (nd_opt->nd_opt_type) {
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case ND_OPT_SOURCE_LL_ADDR:
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case ND_OPT_TARGET_LL_ADDR:
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case ND_OPT_MTU:
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case ND_OPT_NONCE:
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case ND_OPT_REDIRECT_HDR:
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if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
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ND_PRINTK(2, warn,
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"%s: duplicated ND6 option found: type=%d\n",
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__func__, nd_opt->nd_opt_type);
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} else {
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ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
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}
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break;
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case ND_OPT_PREFIX_INFO:
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ndopts->nd_opts_pi_end = nd_opt;
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if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
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ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
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break;
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#ifdef CONFIG_IPV6_ROUTE_INFO
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case ND_OPT_ROUTE_INFO:
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ndopts->nd_opts_ri_end = nd_opt;
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if (!ndopts->nd_opts_ri)
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ndopts->nd_opts_ri = nd_opt;
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break;
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#endif
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default:
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if (ndisc_is_useropt(dev, nd_opt)) {
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ndopts->nd_useropts_end = nd_opt;
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if (!ndopts->nd_useropts)
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ndopts->nd_useropts = nd_opt;
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} else {
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/*
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* Unknown options must be silently ignored,
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* to accommodate future extension to the
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* protocol.
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*/
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ND_PRINTK(2, notice,
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"%s: ignored unsupported option; type=%d, len=%d\n",
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__func__,
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nd_opt->nd_opt_type,
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nd_opt->nd_opt_len);
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}
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}
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next_opt:
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opt_len -= l;
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nd_opt = ((void *)nd_opt) + l;
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}
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return ndopts;
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}
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int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
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{
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switch (dev->type) {
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case ARPHRD_ETHER:
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case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
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case ARPHRD_FDDI:
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ipv6_eth_mc_map(addr, buf);
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return 0;
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case ARPHRD_ARCNET:
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ipv6_arcnet_mc_map(addr, buf);
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return 0;
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case ARPHRD_INFINIBAND:
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ipv6_ib_mc_map(addr, dev->broadcast, buf);
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return 0;
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case ARPHRD_IPGRE:
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return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
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default:
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if (dir) {
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memcpy(buf, dev->broadcast, dev->addr_len);
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return 0;
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}
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}
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return -EINVAL;
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}
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EXPORT_SYMBOL(ndisc_mc_map);
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static u32 ndisc_hash(const void *pkey,
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const struct net_device *dev,
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__u32 *hash_rnd)
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{
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return ndisc_hashfn(pkey, dev, hash_rnd);
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}
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static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
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{
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return neigh_key_eq128(n, pkey);
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}
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static int ndisc_constructor(struct neighbour *neigh)
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{
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struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
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struct net_device *dev = neigh->dev;
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struct inet6_dev *in6_dev;
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struct neigh_parms *parms;
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bool is_multicast = ipv6_addr_is_multicast(addr);
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in6_dev = in6_dev_get(dev);
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if (!in6_dev) {
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return -EINVAL;
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}
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parms = in6_dev->nd_parms;
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__neigh_parms_put(neigh->parms);
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neigh->parms = neigh_parms_clone(parms);
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neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
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if (!dev->header_ops) {
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neigh->nud_state = NUD_NOARP;
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neigh->ops = &ndisc_direct_ops;
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neigh->output = neigh_direct_output;
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} else {
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if (is_multicast) {
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neigh->nud_state = NUD_NOARP;
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ndisc_mc_map(addr, neigh->ha, dev, 1);
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} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
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neigh->nud_state = NUD_NOARP;
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memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
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if (dev->flags&IFF_LOOPBACK)
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neigh->type = RTN_LOCAL;
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} else if (dev->flags&IFF_POINTOPOINT) {
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neigh->nud_state = NUD_NOARP;
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memcpy(neigh->ha, dev->broadcast, dev->addr_len);
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}
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if (dev->header_ops->cache)
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neigh->ops = &ndisc_hh_ops;
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else
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neigh->ops = &ndisc_generic_ops;
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if (neigh->nud_state&NUD_VALID)
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neigh->output = neigh->ops->connected_output;
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else
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neigh->output = neigh->ops->output;
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}
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in6_dev_put(in6_dev);
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return 0;
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}
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static int pndisc_constructor(struct pneigh_entry *n)
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{
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struct in6_addr *addr = (struct in6_addr *)&n->key;
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struct in6_addr maddr;
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struct net_device *dev = n->dev;
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if (!dev || !__in6_dev_get(dev))
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return -EINVAL;
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addrconf_addr_solict_mult(addr, &maddr);
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ipv6_dev_mc_inc(dev, &maddr);
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return 0;
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|
}
|
|
|
|
static void pndisc_destructor(struct pneigh_entry *n)
|
|
{
|
|
struct in6_addr *addr = (struct in6_addr *)&n->key;
|
|
struct in6_addr maddr;
|
|
struct net_device *dev = n->dev;
|
|
|
|
if (!dev || !__in6_dev_get(dev))
|
|
return;
|
|
addrconf_addr_solict_mult(addr, &maddr);
|
|
ipv6_dev_mc_dec(dev, &maddr);
|
|
}
|
|
|
|
/* called with rtnl held */
|
|
static bool ndisc_allow_add(const struct net_device *dev,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
struct inet6_dev *idev = __in6_dev_get(dev);
|
|
|
|
if (!idev || idev->cnf.disable_ipv6) {
|
|
NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
|
|
int len)
|
|
{
|
|
int hlen = LL_RESERVED_SPACE(dev);
|
|
int tlen = dev->needed_tailroom;
|
|
struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
|
|
struct sk_buff *skb;
|
|
|
|
skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
|
|
if (!skb) {
|
|
ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
|
|
__func__);
|
|
return NULL;
|
|
}
|
|
|
|
skb->protocol = htons(ETH_P_IPV6);
|
|
skb->dev = dev;
|
|
|
|
skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
|
|
skb_reset_transport_header(skb);
|
|
|
|
/* Manually assign socket ownership as we avoid calling
|
|
* sock_alloc_send_pskb() to bypass wmem buffer limits
|
|
*/
|
|
skb_set_owner_w(skb, sk);
|
|
|
|
return skb;
|
|
}
|
|
|
|
static void ip6_nd_hdr(struct sk_buff *skb,
|
|
const struct in6_addr *saddr,
|
|
const struct in6_addr *daddr,
|
|
int hop_limit, int len)
|
|
{
|
|
struct ipv6hdr *hdr;
|
|
struct inet6_dev *idev;
|
|
unsigned tclass;
|
|
|
|
rcu_read_lock();
|
|
idev = __in6_dev_get(skb->dev);
|
|
tclass = idev ? idev->cnf.ndisc_tclass : 0;
|
|
rcu_read_unlock();
|
|
|
|
skb_push(skb, sizeof(*hdr));
|
|
skb_reset_network_header(skb);
|
|
hdr = ipv6_hdr(skb);
|
|
|
|
ip6_flow_hdr(hdr, tclass, 0);
|
|
|
|
hdr->payload_len = htons(len);
|
|
hdr->nexthdr = IPPROTO_ICMPV6;
|
|
hdr->hop_limit = hop_limit;
|
|
|
|
hdr->saddr = *saddr;
|
|
hdr->daddr = *daddr;
|
|
}
|
|
|
|
void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
|
|
const struct in6_addr *saddr)
|
|
{
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
struct net *net = dev_net(skb->dev);
|
|
struct sock *sk = net->ipv6.ndisc_sk;
|
|
struct inet6_dev *idev;
|
|
int err;
|
|
struct icmp6hdr *icmp6h = icmp6_hdr(skb);
|
|
u8 type;
|
|
|
|
type = icmp6h->icmp6_type;
|
|
|
|
if (!dst) {
|
|
struct flowi6 fl6;
|
|
int oif = skb->dev->ifindex;
|
|
|
|
icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
|
|
dst = icmp6_dst_alloc(skb->dev, &fl6);
|
|
if (IS_ERR(dst)) {
|
|
kfree_skb(skb);
|
|
return;
|
|
}
|
|
|
|
skb_dst_set(skb, dst);
|
|
}
|
|
|
|
icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
|
|
IPPROTO_ICMPV6,
|
|
csum_partial(icmp6h,
|
|
skb->len, 0));
|
|
|
|
ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len);
|
|
|
|
rcu_read_lock();
|
|
idev = __in6_dev_get(dst->dev);
|
|
IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
|
|
|
|
err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
|
|
net, sk, skb, NULL, dst->dev,
|
|
dst_output);
|
|
if (!err) {
|
|
ICMP6MSGOUT_INC_STATS(net, idev, type);
|
|
ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
}
|
|
EXPORT_SYMBOL(ndisc_send_skb);
|
|
|
|
void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
|
|
const struct in6_addr *solicited_addr,
|
|
bool router, bool solicited, bool override, bool inc_opt)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct in6_addr tmpaddr;
|
|
struct inet6_ifaddr *ifp;
|
|
const struct in6_addr *src_addr;
|
|
struct nd_msg *msg;
|
|
int optlen = 0;
|
|
|
|
/* for anycast or proxy, solicited_addr != src_addr */
|
|
ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
|
|
if (ifp) {
|
|
src_addr = solicited_addr;
|
|
if (ifp->flags & IFA_F_OPTIMISTIC)
|
|
override = false;
|
|
inc_opt |= ifp->idev->cnf.force_tllao;
|
|
in6_ifa_put(ifp);
|
|
} else {
|
|
if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
|
|
inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
|
|
&tmpaddr))
|
|
return;
|
|
src_addr = &tmpaddr;
|
|
}
|
|
|
|
if (!dev->addr_len)
|
|
inc_opt = false;
|
|
if (inc_opt)
|
|
optlen += ndisc_opt_addr_space(dev,
|
|
NDISC_NEIGHBOUR_ADVERTISEMENT);
|
|
|
|
skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
|
|
if (!skb)
|
|
return;
|
|
|
|
msg = skb_put(skb, sizeof(*msg));
|
|
*msg = (struct nd_msg) {
|
|
.icmph = {
|
|
.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
|
|
.icmp6_router = router,
|
|
.icmp6_solicited = solicited,
|
|
.icmp6_override = override,
|
|
},
|
|
.target = *solicited_addr,
|
|
};
|
|
|
|
if (inc_opt)
|
|
ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
|
|
dev->dev_addr,
|
|
NDISC_NEIGHBOUR_ADVERTISEMENT);
|
|
|
|
ndisc_send_skb(skb, daddr, src_addr);
|
|
}
|
|
|
|
static void ndisc_send_unsol_na(struct net_device *dev)
|
|
{
|
|
struct inet6_dev *idev;
|
|
struct inet6_ifaddr *ifa;
|
|
|
|
idev = in6_dev_get(dev);
|
|
if (!idev)
|
|
return;
|
|
|
|
read_lock_bh(&idev->lock);
|
|
list_for_each_entry(ifa, &idev->addr_list, if_list) {
|
|
/* skip tentative addresses until dad completes */
|
|
if (ifa->flags & IFA_F_TENTATIVE &&
|
|
!(ifa->flags & IFA_F_OPTIMISTIC))
|
|
continue;
|
|
|
|
ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
|
|
/*router=*/ !!idev->cnf.forwarding,
|
|
/*solicited=*/ false, /*override=*/ true,
|
|
/*inc_opt=*/ true);
|
|
}
|
|
read_unlock_bh(&idev->lock);
|
|
|
|
in6_dev_put(idev);
|
|
}
|
|
|
|
struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
|
|
const struct in6_addr *saddr, u64 nonce)
|
|
{
|
|
int inc_opt = dev->addr_len;
|
|
struct sk_buff *skb;
|
|
struct nd_msg *msg;
|
|
int optlen = 0;
|
|
|
|
if (!saddr)
|
|
return NULL;
|
|
|
|
if (ipv6_addr_any(saddr))
|
|
inc_opt = false;
|
|
if (inc_opt)
|
|
optlen += ndisc_opt_addr_space(dev,
|
|
NDISC_NEIGHBOUR_SOLICITATION);
|
|
if (nonce != 0)
|
|
optlen += 8;
|
|
|
|
skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
|
|
if (!skb)
|
|
return NULL;
|
|
|
|
msg = skb_put(skb, sizeof(*msg));
|
|
*msg = (struct nd_msg) {
|
|
.icmph = {
|
|
.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
|
|
},
|
|
.target = *solicit,
|
|
};
|
|
|
|
if (inc_opt)
|
|
ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
|
|
dev->dev_addr,
|
|
NDISC_NEIGHBOUR_SOLICITATION);
|
|
if (nonce != 0) {
|
|
u8 *opt = skb_put(skb, 8);
|
|
|
|
opt[0] = ND_OPT_NONCE;
|
|
opt[1] = 8 >> 3;
|
|
memcpy(opt + 2, &nonce, 6);
|
|
}
|
|
|
|
return skb;
|
|
}
|
|
EXPORT_SYMBOL(ndisc_ns_create);
|
|
|
|
void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
|
|
const struct in6_addr *daddr, const struct in6_addr *saddr,
|
|
u64 nonce)
|
|
{
|
|
struct in6_addr addr_buf;
|
|
struct sk_buff *skb;
|
|
|
|
if (!saddr) {
|
|
if (ipv6_get_lladdr(dev, &addr_buf,
|
|
(IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
|
|
return;
|
|
saddr = &addr_buf;
|
|
}
|
|
|
|
skb = ndisc_ns_create(dev, solicit, saddr, nonce);
|
|
|
|
if (skb)
|
|
ndisc_send_skb(skb, daddr, saddr);
|
|
}
|
|
|
|
void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
|
|
const struct in6_addr *daddr)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct rs_msg *msg;
|
|
int send_sllao = dev->addr_len;
|
|
int optlen = 0;
|
|
|
|
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
|
|
/*
|
|
* According to section 2.2 of RFC 4429, we must not
|
|
* send router solicitations with a sllao from
|
|
* optimistic addresses, but we may send the solicitation
|
|
* if we don't include the sllao. So here we check
|
|
* if our address is optimistic, and if so, we
|
|
* suppress the inclusion of the sllao.
|
|
*/
|
|
if (send_sllao) {
|
|
struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
|
|
dev, 1);
|
|
if (ifp) {
|
|
if (ifp->flags & IFA_F_OPTIMISTIC) {
|
|
send_sllao = 0;
|
|
}
|
|
in6_ifa_put(ifp);
|
|
} else {
|
|
send_sllao = 0;
|
|
}
|
|
}
|
|
#endif
|
|
if (send_sllao)
|
|
optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
|
|
|
|
skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
|
|
if (!skb)
|
|
return;
|
|
|
|
msg = skb_put(skb, sizeof(*msg));
|
|
*msg = (struct rs_msg) {
|
|
.icmph = {
|
|
.icmp6_type = NDISC_ROUTER_SOLICITATION,
|
|
},
|
|
};
|
|
|
|
if (send_sllao)
|
|
ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
|
|
dev->dev_addr,
|
|
NDISC_ROUTER_SOLICITATION);
|
|
|
|
ndisc_send_skb(skb, daddr, saddr);
|
|
}
|
|
|
|
|
|
static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
|
|
{
|
|
/*
|
|
* "The sender MUST return an ICMP
|
|
* destination unreachable"
|
|
*/
|
|
dst_link_failure(skb);
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
/* Called with locked neigh: either read or both */
|
|
|
|
static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
|
|
{
|
|
struct in6_addr *saddr = NULL;
|
|
struct in6_addr mcaddr;
|
|
struct net_device *dev = neigh->dev;
|
|
struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
|
|
int probes = atomic_read(&neigh->probes);
|
|
|
|
if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
|
|
dev, false, 1,
|
|
IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
|
|
saddr = &ipv6_hdr(skb)->saddr;
|
|
probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
|
|
if (probes < 0) {
|
|
if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) {
|
|
ND_PRINTK(1, dbg,
|
|
"%s: trying to ucast probe in NUD_INVALID: %pI6\n",
|
|
__func__, target);
|
|
}
|
|
ndisc_send_ns(dev, target, target, saddr, 0);
|
|
} else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
|
|
neigh_app_ns(neigh);
|
|
} else {
|
|
addrconf_addr_solict_mult(target, &mcaddr);
|
|
ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
|
|
}
|
|
}
|
|
|
|
static int pndisc_is_router(const void *pkey,
|
|
struct net_device *dev)
|
|
{
|
|
struct pneigh_entry *n;
|
|
int ret = -1;
|
|
|
|
read_lock_bh(&nd_tbl.lock);
|
|
n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
|
|
if (n)
|
|
ret = !!(n->flags & NTF_ROUTER);
|
|
read_unlock_bh(&nd_tbl.lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
|
|
const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
|
|
struct ndisc_options *ndopts)
|
|
{
|
|
neigh_update(neigh, lladdr, new, flags, 0);
|
|
/* report ndisc ops about neighbour update */
|
|
ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
|
|
}
|
|
|
|
static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
|
|
{
|
|
struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
|
|
const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
|
|
const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
|
|
u8 *lladdr = NULL;
|
|
u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
|
|
offsetof(struct nd_msg, opt));
|
|
struct ndisc_options ndopts;
|
|
struct net_device *dev = skb->dev;
|
|
struct inet6_ifaddr *ifp;
|
|
struct inet6_dev *idev = NULL;
|
|
struct neighbour *neigh;
|
|
int dad = ipv6_addr_any(saddr);
|
|
int is_router = -1;
|
|
SKB_DR(reason);
|
|
u64 nonce = 0;
|
|
bool inc;
|
|
|
|
if (skb->len < sizeof(struct nd_msg))
|
|
return SKB_DROP_REASON_PKT_TOO_SMALL;
|
|
|
|
if (ipv6_addr_is_multicast(&msg->target)) {
|
|
ND_PRINTK(2, warn, "NS: multicast target address\n");
|
|
return reason;
|
|
}
|
|
|
|
/*
|
|
* RFC2461 7.1.1:
|
|
* DAD has to be destined for solicited node multicast address.
|
|
*/
|
|
if (dad && !ipv6_addr_is_solict_mult(daddr)) {
|
|
ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
|
|
return reason;
|
|
}
|
|
|
|
if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
|
|
return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
|
|
|
|
if (ndopts.nd_opts_src_lladdr) {
|
|
lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
|
|
if (!lladdr) {
|
|
ND_PRINTK(2, warn,
|
|
"NS: invalid link-layer address length\n");
|
|
return reason;
|
|
}
|
|
|
|
/* RFC2461 7.1.1:
|
|
* If the IP source address is the unspecified address,
|
|
* there MUST NOT be source link-layer address option
|
|
* in the message.
|
|
*/
|
|
if (dad) {
|
|
ND_PRINTK(2, warn,
|
|
"NS: bad DAD packet (link-layer address option)\n");
|
|
return reason;
|
|
}
|
|
}
|
|
if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
|
|
memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
|
|
|
|
inc = ipv6_addr_is_multicast(daddr);
|
|
|
|
ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
|
|
if (ifp) {
|
|
have_ifp:
|
|
if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
|
|
if (dad) {
|
|
if (nonce != 0 && ifp->dad_nonce == nonce) {
|
|
u8 *np = (u8 *)&nonce;
|
|
/* Matching nonce if looped back */
|
|
ND_PRINTK(2, notice,
|
|
"%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
|
|
ifp->idev->dev->name,
|
|
&ifp->addr, np);
|
|
goto out;
|
|
}
|
|
/*
|
|
* We are colliding with another node
|
|
* who is doing DAD
|
|
* so fail our DAD process
|
|
*/
|
|
addrconf_dad_failure(skb, ifp);
|
|
return reason;
|
|
} else {
|
|
/*
|
|
* This is not a dad solicitation.
|
|
* If we are an optimistic node,
|
|
* we should respond.
|
|
* Otherwise, we should ignore it.
|
|
*/
|
|
if (!(ifp->flags & IFA_F_OPTIMISTIC))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
idev = ifp->idev;
|
|
} else {
|
|
struct net *net = dev_net(dev);
|
|
|
|
/* perhaps an address on the master device */
|
|
if (netif_is_l3_slave(dev)) {
|
|
struct net_device *mdev;
|
|
|
|
mdev = netdev_master_upper_dev_get_rcu(dev);
|
|
if (mdev) {
|
|
ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
|
|
if (ifp)
|
|
goto have_ifp;
|
|
}
|
|
}
|
|
|
|
idev = in6_dev_get(dev);
|
|
if (!idev) {
|
|
/* XXX: count this drop? */
|
|
return reason;
|
|
}
|
|
|
|
if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
|
|
(idev->cnf.forwarding &&
|
|
(net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
|
|
(is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
|
|
if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
|
|
skb->pkt_type != PACKET_HOST &&
|
|
inc &&
|
|
NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
|
|
/*
|
|
* for anycast or proxy,
|
|
* sender should delay its response
|
|
* by a random time between 0 and
|
|
* MAX_ANYCAST_DELAY_TIME seconds.
|
|
* (RFC2461) -- yoshfuji
|
|
*/
|
|
struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
|
|
if (n)
|
|
pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
|
|
goto out;
|
|
}
|
|
} else {
|
|
SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (is_router < 0)
|
|
is_router = idev->cnf.forwarding;
|
|
|
|
if (dad) {
|
|
ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
|
|
!!is_router, false, (ifp != NULL), true);
|
|
goto out;
|
|
}
|
|
|
|
if (inc)
|
|
NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
|
|
else
|
|
NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
|
|
|
|
/*
|
|
* update / create cache entry
|
|
* for the source address
|
|
*/
|
|
neigh = __neigh_lookup(&nd_tbl, saddr, dev,
|
|
!inc || lladdr || !dev->addr_len);
|
|
if (neigh)
|
|
ndisc_update(dev, neigh, lladdr, NUD_STALE,
|
|
NEIGH_UPDATE_F_WEAK_OVERRIDE|
|
|
NEIGH_UPDATE_F_OVERRIDE,
|
|
NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
|
|
if (neigh || !dev->header_ops) {
|
|
ndisc_send_na(dev, saddr, &msg->target, !!is_router,
|
|
true, (ifp != NULL && inc), inc);
|
|
if (neigh)
|
|
neigh_release(neigh);
|
|
reason = SKB_CONSUMED;
|
|
}
|
|
|
|
out:
|
|
if (ifp)
|
|
in6_ifa_put(ifp);
|
|
else
|
|
in6_dev_put(idev);
|
|
return reason;
|
|
}
|
|
|
|
static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
|
|
{
|
|
struct inet6_dev *idev = __in6_dev_get(dev);
|
|
|
|
switch (idev->cnf.accept_untracked_na) {
|
|
case 0: /* Don't accept untracked na (absent in neighbor cache) */
|
|
return 0;
|
|
case 1: /* Create new entries from na if currently untracked */
|
|
return 1;
|
|
case 2: /* Create new entries from untracked na only if saddr is in the
|
|
* same subnet as an address configured on the interface that
|
|
* received the na
|
|
*/
|
|
return !!ipv6_chk_prefix(saddr, dev);
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
|
|
{
|
|
struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
|
|
struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
|
|
const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
|
|
u8 *lladdr = NULL;
|
|
u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
|
|
offsetof(struct nd_msg, opt));
|
|
struct ndisc_options ndopts;
|
|
struct net_device *dev = skb->dev;
|
|
struct inet6_dev *idev = __in6_dev_get(dev);
|
|
struct inet6_ifaddr *ifp;
|
|
struct neighbour *neigh;
|
|
SKB_DR(reason);
|
|
u8 new_state;
|
|
|
|
if (skb->len < sizeof(struct nd_msg))
|
|
return SKB_DROP_REASON_PKT_TOO_SMALL;
|
|
|
|
if (ipv6_addr_is_multicast(&msg->target)) {
|
|
ND_PRINTK(2, warn, "NA: target address is multicast\n");
|
|
return reason;
|
|
}
|
|
|
|
if (ipv6_addr_is_multicast(daddr) &&
|
|
msg->icmph.icmp6_solicited) {
|
|
ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
|
|
return reason;
|
|
}
|
|
|
|
/* For some 802.11 wireless deployments (and possibly other networks),
|
|
* there will be a NA proxy and unsolicitd packets are attacks
|
|
* and thus should not be accepted.
|
|
* drop_unsolicited_na takes precedence over accept_untracked_na
|
|
*/
|
|
if (!msg->icmph.icmp6_solicited && idev &&
|
|
idev->cnf.drop_unsolicited_na)
|
|
return reason;
|
|
|
|
if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
|
|
return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
|
|
|
|
if (ndopts.nd_opts_tgt_lladdr) {
|
|
lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
|
|
if (!lladdr) {
|
|
ND_PRINTK(2, warn,
|
|
"NA: invalid link-layer address length\n");
|
|
return reason;
|
|
}
|
|
}
|
|
ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
|
|
if (ifp) {
|
|
if (skb->pkt_type != PACKET_LOOPBACK
|
|
&& (ifp->flags & IFA_F_TENTATIVE)) {
|
|
addrconf_dad_failure(skb, ifp);
|
|
return reason;
|
|
}
|
|
/* What should we make now? The advertisement
|
|
is invalid, but ndisc specs say nothing
|
|
about it. It could be misconfiguration, or
|
|
an smart proxy agent tries to help us :-)
|
|
|
|
We should not print the error if NA has been
|
|
received from loopback - it is just our own
|
|
unsolicited advertisement.
|
|
*/
|
|
if (skb->pkt_type != PACKET_LOOPBACK)
|
|
ND_PRINTK(1, warn,
|
|
"NA: %pM advertised our address %pI6c on %s!\n",
|
|
eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
|
|
in6_ifa_put(ifp);
|
|
return reason;
|
|
}
|
|
|
|
neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
|
|
|
|
/* RFC 9131 updates original Neighbour Discovery RFC 4861.
|
|
* NAs with Target LL Address option without a corresponding
|
|
* entry in the neighbour cache can now create a STALE neighbour
|
|
* cache entry on routers.
|
|
*
|
|
* entry accept fwding solicited behaviour
|
|
* ------- ------ ------ --------- ----------------------
|
|
* present X X 0 Set state to STALE
|
|
* present X X 1 Set state to REACHABLE
|
|
* absent 0 X X Do nothing
|
|
* absent 1 0 X Do nothing
|
|
* absent 1 1 X Add a new STALE entry
|
|
*
|
|
* Note that we don't do a (daddr == all-routers-mcast) check.
|
|
*/
|
|
new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
|
|
if (!neigh && lladdr && idev && idev->cnf.forwarding) {
|
|
if (accept_untracked_na(dev, saddr)) {
|
|
neigh = neigh_create(&nd_tbl, &msg->target, dev);
|
|
new_state = NUD_STALE;
|
|
}
|
|
}
|
|
|
|
if (neigh && !IS_ERR(neigh)) {
|
|
u8 old_flags = neigh->flags;
|
|
struct net *net = dev_net(dev);
|
|
|
|
if (READ_ONCE(neigh->nud_state) & NUD_FAILED)
|
|
goto out;
|
|
|
|
/*
|
|
* Don't update the neighbor cache entry on a proxy NA from
|
|
* ourselves because either the proxied node is off link or it
|
|
* has already sent a NA to us.
|
|
*/
|
|
if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
|
|
net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
|
|
pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
|
|
/* XXX: idev->cnf.proxy_ndp */
|
|
goto out;
|
|
}
|
|
|
|
ndisc_update(dev, neigh, lladdr,
|
|
new_state,
|
|
NEIGH_UPDATE_F_WEAK_OVERRIDE|
|
|
(msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
|
|
NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
|
|
(msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
|
|
NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
|
|
|
|
if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
|
|
/*
|
|
* Change: router to host
|
|
*/
|
|
rt6_clean_tohost(dev_net(dev), saddr);
|
|
}
|
|
reason = SKB_CONSUMED;
|
|
out:
|
|
neigh_release(neigh);
|
|
}
|
|
return reason;
|
|
}
|
|
|
|
static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb)
|
|
{
|
|
struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
|
|
unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
|
|
struct neighbour *neigh;
|
|
struct inet6_dev *idev;
|
|
const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
|
|
struct ndisc_options ndopts;
|
|
u8 *lladdr = NULL;
|
|
SKB_DR(reason);
|
|
|
|
if (skb->len < sizeof(*rs_msg))
|
|
return SKB_DROP_REASON_PKT_TOO_SMALL;
|
|
|
|
idev = __in6_dev_get(skb->dev);
|
|
if (!idev) {
|
|
ND_PRINTK(1, err, "RS: can't find in6 device\n");
|
|
return reason;
|
|
}
|
|
|
|
/* Don't accept RS if we're not in router mode */
|
|
if (!idev->cnf.forwarding)
|
|
goto out;
|
|
|
|
/*
|
|
* Don't update NCE if src = ::;
|
|
* this implies that the source node has no ip address assigned yet.
|
|
*/
|
|
if (ipv6_addr_any(saddr))
|
|
goto out;
|
|
|
|
/* Parse ND options */
|
|
if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts))
|
|
return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
|
|
|
|
if (ndopts.nd_opts_src_lladdr) {
|
|
lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
|
|
skb->dev);
|
|
if (!lladdr)
|
|
goto out;
|
|
}
|
|
|
|
neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
|
|
if (neigh) {
|
|
ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
|
|
NEIGH_UPDATE_F_WEAK_OVERRIDE|
|
|
NEIGH_UPDATE_F_OVERRIDE|
|
|
NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
|
|
NDISC_ROUTER_SOLICITATION, &ndopts);
|
|
neigh_release(neigh);
|
|
reason = SKB_CONSUMED;
|
|
}
|
|
out:
|
|
return reason;
|
|
}
|
|
|
|
static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
|
|
{
|
|
struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
|
|
struct sk_buff *skb;
|
|
struct nlmsghdr *nlh;
|
|
struct nduseroptmsg *ndmsg;
|
|
struct net *net = dev_net(ra->dev);
|
|
int err;
|
|
int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
|
|
+ (opt->nd_opt_len << 3));
|
|
size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
|
|
|
|
skb = nlmsg_new(msg_size, GFP_ATOMIC);
|
|
if (!skb) {
|
|
err = -ENOBUFS;
|
|
goto errout;
|
|
}
|
|
|
|
nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
|
|
if (!nlh) {
|
|
goto nla_put_failure;
|
|
}
|
|
|
|
ndmsg = nlmsg_data(nlh);
|
|
ndmsg->nduseropt_family = AF_INET6;
|
|
ndmsg->nduseropt_ifindex = ra->dev->ifindex;
|
|
ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
|
|
ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
|
|
ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
|
|
|
|
memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
|
|
|
|
if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
|
|
goto nla_put_failure;
|
|
nlmsg_end(skb, nlh);
|
|
|
|
rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
|
|
return;
|
|
|
|
nla_put_failure:
|
|
nlmsg_free(skb);
|
|
err = -EMSGSIZE;
|
|
errout:
|
|
rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
|
|
}
|
|
|
|
static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
|
|
{
|
|
struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
|
|
bool send_ifinfo_notify = false;
|
|
struct neighbour *neigh = NULL;
|
|
struct ndisc_options ndopts;
|
|
struct fib6_info *rt = NULL;
|
|
struct inet6_dev *in6_dev;
|
|
u32 defrtr_usr_metric;
|
|
unsigned int pref = 0;
|
|
__u32 old_if_flags;
|
|
struct net *net;
|
|
SKB_DR(reason);
|
|
int lifetime;
|
|
int optlen;
|
|
|
|
__u8 *opt = (__u8 *)(ra_msg + 1);
|
|
|
|
optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
|
|
sizeof(struct ra_msg);
|
|
|
|
ND_PRINTK(2, info,
|
|
"RA: %s, dev: %s\n",
|
|
__func__, skb->dev->name);
|
|
if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
|
|
ND_PRINTK(2, warn, "RA: source address is not link-local\n");
|
|
return reason;
|
|
}
|
|
if (optlen < 0)
|
|
return SKB_DROP_REASON_PKT_TOO_SMALL;
|
|
|
|
#ifdef CONFIG_IPV6_NDISC_NODETYPE
|
|
if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
|
|
ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
|
|
return reason;
|
|
}
|
|
#endif
|
|
|
|
in6_dev = __in6_dev_get(skb->dev);
|
|
if (!in6_dev) {
|
|
ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
|
|
skb->dev->name);
|
|
return reason;
|
|
}
|
|
|
|
if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts))
|
|
return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
|
|
|
|
if (!ipv6_accept_ra(in6_dev)) {
|
|
ND_PRINTK(2, info,
|
|
"RA: %s, did not accept ra for dev: %s\n",
|
|
__func__, skb->dev->name);
|
|
goto skip_linkparms;
|
|
}
|
|
|
|
#ifdef CONFIG_IPV6_NDISC_NODETYPE
|
|
/* skip link-specific parameters from interior routers */
|
|
if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
|
|
ND_PRINTK(2, info,
|
|
"RA: %s, nodetype is NODEFAULT, dev: %s\n",
|
|
__func__, skb->dev->name);
|
|
goto skip_linkparms;
|
|
}
|
|
#endif
|
|
|
|
if (in6_dev->if_flags & IF_RS_SENT) {
|
|
/*
|
|
* flag that an RA was received after an RS was sent
|
|
* out on this interface.
|
|
*/
|
|
in6_dev->if_flags |= IF_RA_RCVD;
|
|
}
|
|
|
|
/*
|
|
* Remember the managed/otherconf flags from most recently
|
|
* received RA message (RFC 2462) -- yoshfuji
|
|
*/
|
|
old_if_flags = in6_dev->if_flags;
|
|
in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
|
|
IF_RA_OTHERCONF)) |
|
|
(ra_msg->icmph.icmp6_addrconf_managed ?
|
|
IF_RA_MANAGED : 0) |
|
|
(ra_msg->icmph.icmp6_addrconf_other ?
|
|
IF_RA_OTHERCONF : 0);
|
|
|
|
if (old_if_flags != in6_dev->if_flags)
|
|
send_ifinfo_notify = true;
|
|
|
|
if (!in6_dev->cnf.accept_ra_defrtr) {
|
|
ND_PRINTK(2, info,
|
|
"RA: %s, defrtr is false for dev: %s\n",
|
|
__func__, skb->dev->name);
|
|
goto skip_defrtr;
|
|
}
|
|
|
|
lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
|
|
if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_lft) {
|
|
ND_PRINTK(2, info,
|
|
"RA: router lifetime (%ds) is too short: %s\n",
|
|
lifetime, skb->dev->name);
|
|
goto skip_defrtr;
|
|
}
|
|
|
|
/* Do not accept RA with source-addr found on local machine unless
|
|
* accept_ra_from_local is set to true.
|
|
*/
|
|
net = dev_net(in6_dev->dev);
|
|
if (!in6_dev->cnf.accept_ra_from_local &&
|
|
ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
|
|
ND_PRINTK(2, info,
|
|
"RA from local address detected on dev: %s: default router ignored\n",
|
|
skb->dev->name);
|
|
goto skip_defrtr;
|
|
}
|
|
|
|
#ifdef CONFIG_IPV6_ROUTER_PREF
|
|
pref = ra_msg->icmph.icmp6_router_pref;
|
|
/* 10b is handled as if it were 00b (medium) */
|
|
if (pref == ICMPV6_ROUTER_PREF_INVALID ||
|
|
!in6_dev->cnf.accept_ra_rtr_pref)
|
|
pref = ICMPV6_ROUTER_PREF_MEDIUM;
|
|
#endif
|
|
/* routes added from RAs do not use nexthop objects */
|
|
rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
|
|
if (rt) {
|
|
neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
|
|
rt->fib6_nh->fib_nh_dev, NULL,
|
|
&ipv6_hdr(skb)->saddr);
|
|
if (!neigh) {
|
|
ND_PRINTK(0, err,
|
|
"RA: %s got default router without neighbour\n",
|
|
__func__);
|
|
fib6_info_release(rt);
|
|
return reason;
|
|
}
|
|
}
|
|
/* Set default route metric as specified by user */
|
|
defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
|
|
/* delete the route if lifetime is 0 or if metric needs change */
|
|
if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
|
|
ip6_del_rt(net, rt, false);
|
|
rt = NULL;
|
|
}
|
|
|
|
ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
|
|
rt, lifetime, defrtr_usr_metric, skb->dev->name);
|
|
if (!rt && lifetime) {
|
|
ND_PRINTK(3, info, "RA: adding default router\n");
|
|
|
|
if (neigh)
|
|
neigh_release(neigh);
|
|
|
|
rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
|
|
skb->dev, pref, defrtr_usr_metric);
|
|
if (!rt) {
|
|
ND_PRINTK(0, err,
|
|
"RA: %s failed to add default route\n",
|
|
__func__);
|
|
return reason;
|
|
}
|
|
|
|
neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
|
|
rt->fib6_nh->fib_nh_dev, NULL,
|
|
&ipv6_hdr(skb)->saddr);
|
|
if (!neigh) {
|
|
ND_PRINTK(0, err,
|
|
"RA: %s got default router without neighbour\n",
|
|
__func__);
|
|
fib6_info_release(rt);
|
|
return reason;
|
|
}
|
|
neigh->flags |= NTF_ROUTER;
|
|
} else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
|
|
struct nl_info nlinfo = {
|
|
.nl_net = net,
|
|
};
|
|
rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
|
|
inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
|
|
}
|
|
|
|
if (rt)
|
|
fib6_set_expires(rt, jiffies + (HZ * lifetime));
|
|
if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
|
|
ra_msg->icmph.icmp6_hop_limit) {
|
|
if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
|
|
in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
|
|
fib6_metric_set(rt, RTAX_HOPLIMIT,
|
|
ra_msg->icmph.icmp6_hop_limit);
|
|
} else {
|
|
ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
|
|
}
|
|
}
|
|
|
|
skip_defrtr:
|
|
|
|
/*
|
|
* Update Reachable Time and Retrans Timer
|
|
*/
|
|
|
|
if (in6_dev->nd_parms) {
|
|
unsigned long rtime = ntohl(ra_msg->retrans_timer);
|
|
|
|
if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
|
|
rtime = (rtime*HZ)/1000;
|
|
if (rtime < HZ/100)
|
|
rtime = HZ/100;
|
|
NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
|
|
in6_dev->tstamp = jiffies;
|
|
send_ifinfo_notify = true;
|
|
}
|
|
|
|
rtime = ntohl(ra_msg->reachable_time);
|
|
if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
|
|
rtime = (rtime*HZ)/1000;
|
|
|
|
if (rtime < HZ/10)
|
|
rtime = HZ/10;
|
|
|
|
if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
|
|
NEIGH_VAR_SET(in6_dev->nd_parms,
|
|
BASE_REACHABLE_TIME, rtime);
|
|
NEIGH_VAR_SET(in6_dev->nd_parms,
|
|
GC_STALETIME, 3 * rtime);
|
|
in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
|
|
in6_dev->tstamp = jiffies;
|
|
send_ifinfo_notify = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
skip_linkparms:
|
|
|
|
/*
|
|
* Process options.
|
|
*/
|
|
|
|
if (!neigh)
|
|
neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
|
|
skb->dev, 1);
|
|
if (neigh) {
|
|
u8 *lladdr = NULL;
|
|
if (ndopts.nd_opts_src_lladdr) {
|
|
lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
|
|
skb->dev);
|
|
if (!lladdr) {
|
|
ND_PRINTK(2, warn,
|
|
"RA: invalid link-layer address length\n");
|
|
goto out;
|
|
}
|
|
}
|
|
ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
|
|
NEIGH_UPDATE_F_WEAK_OVERRIDE|
|
|
NEIGH_UPDATE_F_OVERRIDE|
|
|
NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
|
|
NEIGH_UPDATE_F_ISROUTER,
|
|
NDISC_ROUTER_ADVERTISEMENT, &ndopts);
|
|
reason = SKB_CONSUMED;
|
|
}
|
|
|
|
if (!ipv6_accept_ra(in6_dev)) {
|
|
ND_PRINTK(2, info,
|
|
"RA: %s, accept_ra is false for dev: %s\n",
|
|
__func__, skb->dev->name);
|
|
goto out;
|
|
}
|
|
|
|
#ifdef CONFIG_IPV6_ROUTE_INFO
|
|
if (!in6_dev->cnf.accept_ra_from_local &&
|
|
ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
|
|
in6_dev->dev, 0)) {
|
|
ND_PRINTK(2, info,
|
|
"RA from local address detected on dev: %s: router info ignored.\n",
|
|
skb->dev->name);
|
|
goto skip_routeinfo;
|
|
}
|
|
|
|
if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
|
|
struct nd_opt_hdr *p;
|
|
for (p = ndopts.nd_opts_ri;
|
|
p;
|
|
p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
|
|
struct route_info *ri = (struct route_info *)p;
|
|
#ifdef CONFIG_IPV6_NDISC_NODETYPE
|
|
if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
|
|
ri->prefix_len == 0)
|
|
continue;
|
|
#endif
|
|
if (ri->prefix_len == 0 &&
|
|
!in6_dev->cnf.accept_ra_defrtr)
|
|
continue;
|
|
if (ri->lifetime != 0 &&
|
|
ntohl(ri->lifetime) < in6_dev->cnf.accept_ra_min_lft)
|
|
continue;
|
|
if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
|
|
continue;
|
|
if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
|
|
continue;
|
|
rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
|
|
&ipv6_hdr(skb)->saddr);
|
|
}
|
|
}
|
|
|
|
skip_routeinfo:
|
|
#endif
|
|
|
|
#ifdef CONFIG_IPV6_NDISC_NODETYPE
|
|
/* skip link-specific ndopts from interior routers */
|
|
if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
|
|
ND_PRINTK(2, info,
|
|
"RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
|
|
__func__, skb->dev->name);
|
|
goto out;
|
|
}
|
|
#endif
|
|
|
|
if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
|
|
struct nd_opt_hdr *p;
|
|
for (p = ndopts.nd_opts_pi;
|
|
p;
|
|
p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
|
|
addrconf_prefix_rcv(skb->dev, (u8 *)p,
|
|
(p->nd_opt_len) << 3,
|
|
ndopts.nd_opts_src_lladdr != NULL);
|
|
}
|
|
}
|
|
|
|
if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
|
|
__be32 n;
|
|
u32 mtu;
|
|
|
|
memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
|
|
mtu = ntohl(n);
|
|
|
|
if (in6_dev->ra_mtu != mtu) {
|
|
in6_dev->ra_mtu = mtu;
|
|
send_ifinfo_notify = true;
|
|
}
|
|
|
|
if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
|
|
ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
|
|
} else if (in6_dev->cnf.mtu6 != mtu) {
|
|
in6_dev->cnf.mtu6 = mtu;
|
|
fib6_metric_set(rt, RTAX_MTU, mtu);
|
|
rt6_mtu_change(skb->dev, mtu);
|
|
}
|
|
}
|
|
|
|
if (ndopts.nd_useropts) {
|
|
struct nd_opt_hdr *p;
|
|
for (p = ndopts.nd_useropts;
|
|
p;
|
|
p = ndisc_next_useropt(skb->dev, p,
|
|
ndopts.nd_useropts_end)) {
|
|
ndisc_ra_useropt(skb, p);
|
|
}
|
|
}
|
|
|
|
if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
|
|
ND_PRINTK(2, warn, "RA: invalid RA options\n");
|
|
}
|
|
out:
|
|
/* Send a notify if RA changed managed/otherconf flags or
|
|
* timer settings or ra_mtu value
|
|
*/
|
|
if (send_ifinfo_notify)
|
|
inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
|
|
|
|
fib6_info_release(rt);
|
|
if (neigh)
|
|
neigh_release(neigh);
|
|
return reason;
|
|
}
|
|
|
|
static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb)
|
|
{
|
|
struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
|
|
u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
|
|
offsetof(struct rd_msg, opt));
|
|
struct ndisc_options ndopts;
|
|
SKB_DR(reason);
|
|
u8 *hdr;
|
|
|
|
#ifdef CONFIG_IPV6_NDISC_NODETYPE
|
|
switch (skb->ndisc_nodetype) {
|
|
case NDISC_NODETYPE_HOST:
|
|
case NDISC_NODETYPE_NODEFAULT:
|
|
ND_PRINTK(2, warn,
|
|
"Redirect: from host or unauthorized router\n");
|
|
return reason;
|
|
}
|
|
#endif
|
|
|
|
if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
|
|
ND_PRINTK(2, warn,
|
|
"Redirect: source address is not link-local\n");
|
|
return reason;
|
|
}
|
|
|
|
if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
|
|
return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
|
|
|
|
if (!ndopts.nd_opts_rh) {
|
|
ip6_redirect_no_header(skb, dev_net(skb->dev),
|
|
skb->dev->ifindex);
|
|
return reason;
|
|
}
|
|
|
|
hdr = (u8 *)ndopts.nd_opts_rh;
|
|
hdr += 8;
|
|
if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
|
|
return SKB_DROP_REASON_PKT_TOO_SMALL;
|
|
|
|
return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
|
|
}
|
|
|
|
static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
|
|
struct sk_buff *orig_skb,
|
|
int rd_len)
|
|
{
|
|
u8 *opt = skb_put(skb, rd_len);
|
|
|
|
memset(opt, 0, 8);
|
|
*(opt++) = ND_OPT_REDIRECT_HDR;
|
|
*(opt++) = (rd_len >> 3);
|
|
opt += 6;
|
|
|
|
skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
|
|
rd_len - 8);
|
|
}
|
|
|
|
void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
|
|
{
|
|
struct net_device *dev = skb->dev;
|
|
struct net *net = dev_net(dev);
|
|
struct sock *sk = net->ipv6.ndisc_sk;
|
|
int optlen = 0;
|
|
struct inet_peer *peer;
|
|
struct sk_buff *buff;
|
|
struct rd_msg *msg;
|
|
struct in6_addr saddr_buf;
|
|
struct rt6_info *rt;
|
|
struct dst_entry *dst;
|
|
struct flowi6 fl6;
|
|
int rd_len;
|
|
u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
|
|
ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
|
|
bool ret;
|
|
|
|
if (netif_is_l3_master(skb->dev)) {
|
|
dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
|
|
if (!dev)
|
|
return;
|
|
}
|
|
|
|
if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
|
|
ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
|
|
dev->name);
|
|
return;
|
|
}
|
|
|
|
if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
|
|
ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
|
|
ND_PRINTK(2, warn,
|
|
"Redirect: target address is not link-local unicast\n");
|
|
return;
|
|
}
|
|
|
|
icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
|
|
&saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
|
|
|
|
dst = ip6_route_output(net, NULL, &fl6);
|
|
if (dst->error) {
|
|
dst_release(dst);
|
|
return;
|
|
}
|
|
dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
|
|
if (IS_ERR(dst))
|
|
return;
|
|
|
|
rt = (struct rt6_info *) dst;
|
|
|
|
if (rt->rt6i_flags & RTF_GATEWAY) {
|
|
ND_PRINTK(2, warn,
|
|
"Redirect: destination is not a neighbour\n");
|
|
goto release;
|
|
}
|
|
peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
|
|
ret = inet_peer_xrlim_allow(peer, 1*HZ);
|
|
if (peer)
|
|
inet_putpeer(peer);
|
|
if (!ret)
|
|
goto release;
|
|
|
|
if (dev->addr_len) {
|
|
struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
|
|
if (!neigh) {
|
|
ND_PRINTK(2, warn,
|
|
"Redirect: no neigh for target address\n");
|
|
goto release;
|
|
}
|
|
|
|
read_lock_bh(&neigh->lock);
|
|
if (neigh->nud_state & NUD_VALID) {
|
|
memcpy(ha_buf, neigh->ha, dev->addr_len);
|
|
read_unlock_bh(&neigh->lock);
|
|
ha = ha_buf;
|
|
optlen += ndisc_redirect_opt_addr_space(dev, neigh,
|
|
ops_data_buf,
|
|
&ops_data);
|
|
} else
|
|
read_unlock_bh(&neigh->lock);
|
|
|
|
neigh_release(neigh);
|
|
}
|
|
|
|
rd_len = min_t(unsigned int,
|
|
IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
|
|
skb->len + 8);
|
|
rd_len &= ~0x7;
|
|
optlen += rd_len;
|
|
|
|
buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
|
|
if (!buff)
|
|
goto release;
|
|
|
|
msg = skb_put(buff, sizeof(*msg));
|
|
*msg = (struct rd_msg) {
|
|
.icmph = {
|
|
.icmp6_type = NDISC_REDIRECT,
|
|
},
|
|
.target = *target,
|
|
.dest = ipv6_hdr(skb)->daddr,
|
|
};
|
|
|
|
/*
|
|
* include target_address option
|
|
*/
|
|
|
|
if (ha)
|
|
ndisc_fill_redirect_addr_option(buff, ha, ops_data);
|
|
|
|
/*
|
|
* build redirect option and copy skb over to the new packet.
|
|
*/
|
|
|
|
if (rd_len)
|
|
ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
|
|
|
|
skb_dst_set(buff, dst);
|
|
ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
|
|
return;
|
|
|
|
release:
|
|
dst_release(dst);
|
|
}
|
|
|
|
static void pndisc_redo(struct sk_buff *skb)
|
|
{
|
|
enum skb_drop_reason reason = ndisc_recv_ns(skb);
|
|
|
|
kfree_skb_reason(skb, reason);
|
|
}
|
|
|
|
static int ndisc_is_multicast(const void *pkey)
|
|
{
|
|
return ipv6_addr_is_multicast((struct in6_addr *)pkey);
|
|
}
|
|
|
|
static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
|
|
{
|
|
struct inet6_dev *idev = __in6_dev_get(skb->dev);
|
|
|
|
if (!idev)
|
|
return true;
|
|
if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
|
|
idev->cnf.suppress_frag_ndisc) {
|
|
net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
|
|
{
|
|
struct nd_msg *msg;
|
|
SKB_DR(reason);
|
|
|
|
if (ndisc_suppress_frag_ndisc(skb))
|
|
return SKB_DROP_REASON_IPV6_NDISC_FRAG;
|
|
|
|
if (skb_linearize(skb))
|
|
return SKB_DROP_REASON_NOMEM;
|
|
|
|
msg = (struct nd_msg *)skb_transport_header(skb);
|
|
|
|
__skb_push(skb, skb->data - skb_transport_header(skb));
|
|
|
|
if (ipv6_hdr(skb)->hop_limit != 255) {
|
|
ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
|
|
ipv6_hdr(skb)->hop_limit);
|
|
return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT;
|
|
}
|
|
|
|
if (msg->icmph.icmp6_code != 0) {
|
|
ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
|
|
msg->icmph.icmp6_code);
|
|
return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE;
|
|
}
|
|
|
|
switch (msg->icmph.icmp6_type) {
|
|
case NDISC_NEIGHBOUR_SOLICITATION:
|
|
memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
|
|
reason = ndisc_recv_ns(skb);
|
|
break;
|
|
|
|
case NDISC_NEIGHBOUR_ADVERTISEMENT:
|
|
reason = ndisc_recv_na(skb);
|
|
break;
|
|
|
|
case NDISC_ROUTER_SOLICITATION:
|
|
reason = ndisc_recv_rs(skb);
|
|
break;
|
|
|
|
case NDISC_ROUTER_ADVERTISEMENT:
|
|
reason = ndisc_router_discovery(skb);
|
|
break;
|
|
|
|
case NDISC_REDIRECT:
|
|
reason = ndisc_redirect_rcv(skb);
|
|
break;
|
|
}
|
|
|
|
return reason;
|
|
}
|
|
|
|
static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
|
|
{
|
|
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
|
|
struct netdev_notifier_change_info *change_info;
|
|
struct net *net = dev_net(dev);
|
|
struct inet6_dev *idev;
|
|
bool evict_nocarrier;
|
|
|
|
switch (event) {
|
|
case NETDEV_CHANGEADDR:
|
|
neigh_changeaddr(&nd_tbl, dev);
|
|
fib6_run_gc(0, net, false);
|
|
fallthrough;
|
|
case NETDEV_UP:
|
|
idev = in6_dev_get(dev);
|
|
if (!idev)
|
|
break;
|
|
if (idev->cnf.ndisc_notify ||
|
|
net->ipv6.devconf_all->ndisc_notify)
|
|
ndisc_send_unsol_na(dev);
|
|
in6_dev_put(idev);
|
|
break;
|
|
case NETDEV_CHANGE:
|
|
idev = in6_dev_get(dev);
|
|
if (!idev)
|
|
evict_nocarrier = true;
|
|
else {
|
|
evict_nocarrier = idev->cnf.ndisc_evict_nocarrier &&
|
|
net->ipv6.devconf_all->ndisc_evict_nocarrier;
|
|
in6_dev_put(idev);
|
|
}
|
|
|
|
change_info = ptr;
|
|
if (change_info->flags_changed & IFF_NOARP)
|
|
neigh_changeaddr(&nd_tbl, dev);
|
|
if (evict_nocarrier && !netif_carrier_ok(dev))
|
|
neigh_carrier_down(&nd_tbl, dev);
|
|
break;
|
|
case NETDEV_DOWN:
|
|
neigh_ifdown(&nd_tbl, dev);
|
|
fib6_run_gc(0, net, false);
|
|
break;
|
|
case NETDEV_NOTIFY_PEERS:
|
|
ndisc_send_unsol_na(dev);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static struct notifier_block ndisc_netdev_notifier = {
|
|
.notifier_call = ndisc_netdev_event,
|
|
.priority = ADDRCONF_NOTIFY_PRIORITY - 5,
|
|
};
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
|
|
const char *func, const char *dev_name)
|
|
{
|
|
static char warncomm[TASK_COMM_LEN];
|
|
static int warned;
|
|
if (strcmp(warncomm, current->comm) && warned < 5) {
|
|
strcpy(warncomm, current->comm);
|
|
pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
|
|
warncomm, func,
|
|
dev_name, ctl->procname,
|
|
dev_name, ctl->procname);
|
|
warned++;
|
|
}
|
|
}
|
|
|
|
int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
|
|
size_t *lenp, loff_t *ppos)
|
|
{
|
|
struct net_device *dev = ctl->extra1;
|
|
struct inet6_dev *idev;
|
|
int ret;
|
|
|
|
if ((strcmp(ctl->procname, "retrans_time") == 0) ||
|
|
(strcmp(ctl->procname, "base_reachable_time") == 0))
|
|
ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
|
|
|
|
if (strcmp(ctl->procname, "retrans_time") == 0)
|
|
ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
|
|
|
|
else if (strcmp(ctl->procname, "base_reachable_time") == 0)
|
|
ret = neigh_proc_dointvec_jiffies(ctl, write,
|
|
buffer, lenp, ppos);
|
|
|
|
else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
|
|
(strcmp(ctl->procname, "base_reachable_time_ms") == 0))
|
|
ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
|
|
buffer, lenp, ppos);
|
|
else
|
|
ret = -1;
|
|
|
|
if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
|
|
if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
|
|
idev->nd_parms->reachable_time =
|
|
neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
|
|
idev->tstamp = jiffies;
|
|
inet6_ifinfo_notify(RTM_NEWLINK, idev);
|
|
in6_dev_put(idev);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
|
|
#endif
|
|
|
|
static int __net_init ndisc_net_init(struct net *net)
|
|
{
|
|
struct ipv6_pinfo *np;
|
|
struct sock *sk;
|
|
int err;
|
|
|
|
err = inet_ctl_sock_create(&sk, PF_INET6,
|
|
SOCK_RAW, IPPROTO_ICMPV6, net);
|
|
if (err < 0) {
|
|
ND_PRINTK(0, err,
|
|
"NDISC: Failed to initialize the control socket (err %d)\n",
|
|
err);
|
|
return err;
|
|
}
|
|
|
|
net->ipv6.ndisc_sk = sk;
|
|
|
|
np = inet6_sk(sk);
|
|
np->hop_limit = 255;
|
|
/* Do not loopback ndisc messages */
|
|
inet6_clear_bit(MC6_LOOP, sk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit ndisc_net_exit(struct net *net)
|
|
{
|
|
inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
|
|
}
|
|
|
|
static struct pernet_operations ndisc_net_ops = {
|
|
.init = ndisc_net_init,
|
|
.exit = ndisc_net_exit,
|
|
};
|
|
|
|
int __init ndisc_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = register_pernet_subsys(&ndisc_net_ops);
|
|
if (err)
|
|
return err;
|
|
/*
|
|
* Initialize the neighbour table
|
|
*/
|
|
neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
err = neigh_sysctl_register(NULL, &nd_tbl.parms,
|
|
ndisc_ifinfo_sysctl_change);
|
|
if (err)
|
|
goto out_unregister_pernet;
|
|
out:
|
|
#endif
|
|
return err;
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
out_unregister_pernet:
|
|
unregister_pernet_subsys(&ndisc_net_ops);
|
|
goto out;
|
|
#endif
|
|
}
|
|
|
|
int __init ndisc_late_init(void)
|
|
{
|
|
return register_netdevice_notifier(&ndisc_netdev_notifier);
|
|
}
|
|
|
|
void ndisc_late_cleanup(void)
|
|
{
|
|
unregister_netdevice_notifier(&ndisc_netdev_notifier);
|
|
}
|
|
|
|
void ndisc_cleanup(void)
|
|
{
|
|
#ifdef CONFIG_SYSCTL
|
|
neigh_sysctl_unregister(&nd_tbl.parms);
|
|
#endif
|
|
neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
|
|
unregister_pernet_subsys(&ndisc_net_ops);
|
|
}
|